They were using United Airlines passes. This has nothing to do with discrimination that you seem to want to make this about. All the airlines have very clear policies that employees, family members, and friends for dress code. This dress code does not the same as for regular paying passengers. You say the father was wearing shorts. It is policy that pass riders can wear shorts. The girls could have worn shorts and there would be no problem. If the father was wearing leggings and the girls were wearing shorts, you would see the father stopped from boarding. And if he did, would you write the same article? When I first started with Continental Airlines years ago, men had to wear suits to use these passes on flights. Women did not have to wear suits.